Overlay pieces
are made of two layers. The bottom layer is a solid sterling silver piece. The
top layer has a cutout design. The cutout is placed over the bottom layer and
the two pieces are "sweated" together, that is heated so that they become
one.

The bottom layer (background to
the cutout) is usually accented. The Navajo silversmiths oxidize the bottom layer
which darkens it. Hopi silversmiths oxidize and etch the background (texturize
it) with hashmarks.